Surgical stapling device with laminated drive member

ABSTRACT

A surgical stapling device includes an elongate body, a tool assembly pivotably coupled to the elongate body for articulation, and a drive assembly. The drive assembly is movable in relation to the tool assembly to eject staples from the tool assembly and cut tissue clamped between jaws of the tool assembly. The drive assembly includes a working end that is coupled to a flexible drive beam. The flexible drive beam includes a metallic core member and outer laminates secured to opposite sides of the core member. The outer laminates are formed of a material having a lower coefficient of friction than the core member to minimize firing forces of the surgical stapling device.

FIELD

This disclosure is generally related to a surgical stapling device with a drive assembly including a flexible drive beam and, more particularly, to a surgical stapling device including an articulating tool assembly and a drive assembly having a flexible drive beam.

BACKGROUND

Endoscopic stapling devices that include an elongate body, and a tool assembly supported on the elongate body are well known. Typically, the tool assembly is coupled to a distal portion of the elongate body by a pivot member that defines a pivot axis that is transverse to a longitudinal axis of the elongate body such that the tool assembly can pivot between articulated and non-articulated positions. Such stapling devices include a drive assembly having a flexible drive beam that can bend about the pivot axis when the tool assembly is fired to eject staples from the tool assembly.

To gain better access to tissue within a body cavity during an endoscopic surgical procedure, articulation of the tool assembly over a range of ninety-degrees is desirable. However, firing the stapling device with the tool assembly articulated to such high degrees greatly increases the firing forces required to fire the stapling device.

A continuing need exists in the art for a stapling device that can minimize the firing forces required to fire the stapling device when the tool assembly of the stapling device is in an articulated position.

SUMMARY

This disclosure generally relates to a surgical stapling device that includes an elongate body, a tool assembly pivotably coupled to the elongate body for articulation, and a drive assembly. The drive assembly includes a working end that is coupled to a flexible drive beam. The flexible drive beam has a metallic core member and outer laminates secured to opposite sides of the core member. The outer laminates are formed of a material having a lower coefficient of friction than the core member to minimize firing forces of the surgical stapling device.

Aspects of the disclosure are directed to a drive assembly including a working end and a drive beam assembly. The working end has an I-beam configuration and includes a first beam, a second beam, and a vertical strut interconnecting the first beam to the second beam. The drive beam assembly includes a core member and outer laminates. The core member includes a flexible beam having planar side walls, a top wall, and a bottom wall. The flexible beam has a distal portion that is secured to the working end and the outer laminates are supported along the planar side walls of the flexible beam. The core member is formed from a metal and the outer laminates are formed from a material having a lower coefficient of friction than the core member.

Other aspects of the disclosure are directed to a stapling device including an adapter assembly, a tool assembly, and a drive assembly. The adapter assembly defines a longitudinal axis and has a proximal portion and a distal portion. The tool assembly is supported on the distal portion of the adapter assembly by a pivot member that defines a pivot axis that is transverse to the longitudinal axis such that the tool assembly can articulate between a non-articulated position and articulated positions about the pivot axis. The tool assembly includes an anvil assembly and a cartridge assembly that are movable in relation to each other between open and clamped positions. The drive assembly is movable in relation to the tool assembly between retracted and advanced positions to actuate the tool assembly and includes a working end and a drive beam assembly. The working end has an I-beam configuration and includes a first beam, a second beam, and a vertical strut interconnecting the first beam to the second beam. The drive beam assembly includes a core member and outer laminates. The core member includes a flexible beam having planar side walls, a top wall, and a bottom wall. The flexible beam has a distal portion secured to the working end, and the outer laminates are supported along the planar side walls of the flexible beam. The core member is formed from a metal and the outer laminates are formed from a material having a lower coefficient of friction than the core member.

In aspects of the disclosure, the outer laminates are formed from polytetrafluoroethylene.

In some aspects of the disclosure, the core member is formed from stainless steel.

In certain aspects of the disclosure, the outer laminates are coupled together by a top wall to form a U-shaped laminate assembly that defines a cavity and an opening opposite the top wall.

In aspects of the disclosure, the cavity receives the core member through the opening.

In some aspects of the disclosure, the bottom wall of the core member defines notches and one of the outer laminates includes fingers that are aligned with the notches and extend into the opening.

In certain aspects of the disclosure, the fingers are received within the notches in snap-fit fashion when the U-shaped laminate assembly is positioned on the core member to secure the U-shaped laminate assembly on the core member.

In some aspects of the disclosure, the core member defines openings, and each of the outer laminates defines openings that are aligned with the openings in the core member.

In certain aspects of the disclosure, the openings in the outer laminates are bounded by inwardly projecting ribs that are received within the openings in the core member, and the inwardly extending ribs on the outer laminates are secured together within the openings of the core member to secure the outer laminates to opposite sides of the core member.

In aspects of the disclosure, the outer laminates are coupled together with top and bottom walls to form a rectangular laminate assembly that defines a cavity that receives the core member.

In some aspects of the disclosure, each of the top and bottom walls of the core member includes a protrusion and each of the top and bottom walls of the rectangular laminate assembly defines a cutout that receives one of the protrusions to secure the rectangular laminate assembly on the core member.

In certain aspects of the disclosure, each of the outer laminates includes a distal extension that defines a cutout, and the working end of the drive assembly includes protrusions that are received within the cutouts to secure the rectangular laminate assembly to the core member.

In aspects of the disclosure, the outer laminates and the core member define openings and the rectangular laminate assembly is secured to the core member with fasteners selected from the group consisting of pins, dowels, rivets, and grommets, that extend through the openings.

In some aspects of the disclosure, each of the outer laminates defines an opening and includes a protrusion, and the core member includes elongate slots that receive the protrusions of the outer laminates.

In certain aspects of the disclosure, the protrusion of each of the outer laminates is received within the opening of the other of the outer laminates to secure the outer laminates to each other and to the core member.

In aspects of the disclosure, the elongate slots in the core member facilitate relative movement between the outer laminates and the core member.

Other aspects, features, and advantages will be apparent from the description, the drawings, and the claims that follow.

BRIEF DESCRIPTION OF DRAWINGS

Various aspects and features of the disclosure are described with reference to the drawings wherein like numerals designate identical or corresponding elements in each of the several views wherein:

FIG. 1 is a side perspective view from a distal end of a surgical stapling device according to aspects of the disclosure with a tool assembly of the stapling device in a clamped and non-articulated position and the tool assembly shown in phantom in the clamped and articulated positions;

FIG. 2 is a side perspective view of a reload assembly of the surgical stapling device shown in FIG. 1 with the tool assembly in a non-articulated, open position;

FIG. 3 is a side perspective partially exploded view of the reload assembly shown in FIG. 2 with the tool assembly shown in the open position;

FIG. 4 is a side perspective exploded view of a drive assembly of the stapling device shown in FIG. 3 ;

FIG. 5 is a cross-sectional view taken along section line 5-5 of FIG. 4 ;

FIG. 6 is an enlarged view of the indicated area of detail shown in FIG. 3 ;

FIG. 7 is a cross-sectional view taken through a drive beam and outer laminates of the drive assembly shown in FIG. 6 as the outer laminates are positioned onto the drive beam;

FIG. 8 is a cross-sectional view through the drive assembly taken along section line 8-8 of FIG. 6 ;

FIG. 9 is a cross-sectional view taken along section line 9-9 of FIG. 8 ;

FIG. 10 is a top view of the tool assembly of the stapling device shown in FIG. 1 with the tool assembly in the clamped position and the drive assembly in a partially retracted position;

FIG. 11 is a top view of the tool assembly of the stapling device shown in FIG. 1 with the tool assembly in the clamped position and the drive assembly in an advanced position;

FIG. 12 is a side perspective view of an alternate version of the drive assembly of the surgical stapling device shown in FIG. 1 ;

FIG. 13 is a cross-sectional view taken through the drive assembly along section line 13-13 of FIG. 12 ;

FIG. 14 is an exploded view of the drive assembly shown in FIG. 12 ;

FIG. 15 is a side perspective view of a distal portion of another alternate version of the drive assembly of the surgical stapling device shown in FIG. 1 ;

FIG. 16 is a side view of the distal portion of the drive assembly shown in FIG. 15 with parts separated;

FIG. 17 is a cross-sectional view taken through the drive assembly along section line 17-17 of FIG. 15 as the outer laminates are positioned onto the drive beam;

FIG. 18 is a cross-sectional view taken through the drive assembly along section line 18-18 of FIG. 15 with the outer laminates secured to the drive beam;

FIG. 19 is a side perspective view of a distal portion of yet another alternate version of the drive assembly of the surgical stapling device shown in FIG. 1 ;

FIG. 20 is a side view of the distal portion of the drive assembly shown in FIG. 19 with parts separated;

FIG. 21 is a side perspective view with parts separated of another alternate version of the drive assembly of the surgical stapling device shown in FIG. 1 ;

FIG. 22 is a side perspective view with parts separated of another alternate version of the drive assembly of the surgical stapling device shown in FIG. 1 ;

FIG. 23 is a side perspective view of a distal portion of the drive assembly shown in FIG. 22 assembled;

FIG. 24 is a cross-sectional view taken along section line 24-24 of FIG. 23 ;

FIG. 25 is a cross-sectional view of a portion of another alternate version of the drive assembly of the surgical stapling device shown in FIG. 1 ; and

FIG. 26 is a cross-sectional view of a portion of yet another alternate version of the drive assembly of the surgical stapling device shown in FIG. 1 .

DETAILED DESCRIPTION

The disclosed surgical stapling device will now be described in detail with reference to the drawings in which like reference numerals designate identical or corresponding elements in each of the several views. However, it is to be understood that aspects of the disclosure included herein are merely exemplary of the disclosure and may be embodied in various forms. Well-known functions or constructions are not described in detail to avoid obscuring the disclosure in unnecessary detail. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the disclosure in virtually any appropriately detailed structure. In addition, directional terms such as front, rear, upper, lower, top, bottom, and similar terms are used to assist in understanding the description and are not intended to limit the disclosure.

In this description, the term “proximal” is used generally to refer to that portion of the device that is closer to a clinician during use of the device for its intended purpose, while the term “distal” is used generally to refer to that portion of the device that is farther from the clinician during use of the device for its intended purpose. In addition, the terms “about” and “substantially” are intended to include a range that includes the listed parameter and plus or minus ten percent of the listed parameter. Further, the term “clinician” is used generally to refer to medical personnel including doctors, nurses, and support personnel.

This disclosure is directed to a surgical stapling device that includes an elongate body, a tool assembly, and a drive assembly. The drive assembly is movable in relation to the tool assembly to eject staples from the tool assembly and cut tissue clamped between jaws of the tool assembly. The tool assembly is secured to the elongate body by a pivot member that defines a pivot axis that is transverse to a longitudinal axis of the elongate body such that the tool assembly can articulate about the pivot axis between a non-articulated position and articulated positions. The drive assembly includes a working end that is coupled to a flexible drive beam. The flexible drive beam includes a metallic core member and outer laminates that are formed of a material having a lower coefficient of friction than the core member and are secured about the core to minimize firing forces of the surgical stapling device.

FIG. 1 illustrates a surgical stapling device shown generally as stapling device 10 that includes a handle assembly 12, an elongate body or adapter assembly 14, and a tool assembly 16. In aspects of the disclosure, the handle assembly 12 is powered and includes a stationary handgrip 18 and actuation buttons 20. The actuation buttons 20 are operable to actuate various functions of the tool assembly 16 via the adapter assembly 14 including approximation, stapling, and cutting of tissue. Although not shown, the handle assembly 16 can support batteries (not shown) that provide energy to the handle assembly 12 to actuate the stapling device 10. Although the stapling device 10 is illustrated as a powered stapling device, it is envisioned that the advantages of this disclosure are suitable for use with manually powered surgical stapling devices as well as robotically controlled stapling devices.

In aspects of the disclosure, the tool assembly 16 forms part of a reload assembly 22 that includes the tool assembly 16 and a body portion 24. The body portion 24 has a proximal portion that is releasably coupled to the adapter assembly 14 (FIG. 1 ) of the stapling device 10 and a distal portion that supports the tool assembly 16. It is envisioned that the tool assembly 16 need not form part of a reload assembly 22 but can be fixedly connected to a distal portion of the adapter assembly 14.

FIGS. 2 and 3 illustrate the reload assembly 22 with the tool assembly 16 supported on the distal portion of the body portion 24 by a pivot member 26 and coupling members 28. The pivot member 26 is supported on a mounting member 30 that is secured to a proximal portion of the tool assembly 16 and defines a pivot axis “Z” (FIG. 1 ) that is transverse to a longitudinal axis “X” (FIG. 1 ) of the body portion 24 of the reload assembly 24 of the adapter assembly 14. Each of the coupling members 28 have a distal portion that is coupled to the pivot member 26 and a proximal portion that is fixedly secured to the body portion 24 of the reload assembly 22 such that the tool assembly 16 can pivot about the pivot axis “Z”.

The tool assembly 16 includes an anvil assembly 32 and a cartridge assembly 34. The anvil assembly 32 includes an anvil plate 36 that defines staple forming pockets 38 (FIG. 2 ) and a central knife slot 40. The staple forming pockets 38 are aligned in rows on opposite sides of the central knife slot 40 and receive staples (not shown) that are ejected from the cartridge assembly 34 when the stapling device 10 is fired to form the staples in tissue clamped between the anvil and cartridge assemblies 32 and 34.

The cartridge assembly 34 includes a channel member 42 and a staple cartridge 44 that is supported within the channel member 42. The staple cartridge 44 defines staple slots 46 (FIG. 3 ) and a central knife slot 48. The staple slots 46 are aligned in rows on opposite sides of the central knife slot 48 and receive staples (not shown). The channel member 42 also defines a central knife slot 48 a that is axially aligned with the knife slot 48 in the staple cartridge 44. In aspects of the disclosure, the anvil assembly 32 is fixedly secured to the mounting member 30 and the cartridge assembly 34 is pivotably supported on the mounting member 30 such that the cartridge assembly 34 is movable in relation to the anvil assembly 32 between open and clamped positions. In the clamped position, the anvil plate 36 of the anvil assembly 32 is in juxtaposed alignment with the staple cartridge 44 of the cartridge assembly 34. It is envisioned that the anvil assembly 32 could be pivotably secured to the mounting member 30 and the cartridge assembly 34 could be fixedly secured to the mounting member 30. U.S. Pat. No. 7,891,534 (“the '534 Patent”) discloses a tool assembly in detail suitable for use with the stapling device 10.

The body portion 24 of the reload assembly 22 includes a body 50, a drive assembly 52, and an outer tube 54. In aspects of the disclosure, the body 50 is formed of body half-sections 50 a and 50 b that, when secured together, form a longitudinal channel 56 that receives the drive assembly 52 to facilitate movement of the drive assembly 52 between retracted and advanced positions within the body 50. The body 50 is received within the outer tube 54 when the body half-sections 50 a and 50 b are assembled.

FIGS. 4-9 illustrate the drive assembly 52 which includes a working end 60 and a flexible drive beam assembly 62. The working end 60 of the drive assembly 52 has an I-beam configuration and includes a first beam 64, a second beam 66, and a vertical strut 68 that fixedly couples the first beam 64 to the second beam 66. In aspects of the disclosure, the vertical strut 68 supports or includes a distally facing cutting edge 71. The working end 60 of the drive assembly 52 is received within and movable through the tool assembly 16 to move the tool assembly 16 between the open and clamped positions and to fire staples from the staple cartridge 44. For a more detailed description of the interaction of the working end 60 of the drive assembly 52 and the tool assembly 16, see the '534 Patent.

The drive beam assembly 62 includes a metallic core member 70 and outer laminates 72 that are positioned on opposite sides of the core member 70. The core member 70 includes a flexible beam 74 having planar side walls 76, a top wall 78, and a bottom wall 80, a proximal portion, and a distal portion. The distal portion of the flexible beam 74 is coupled to the working end 60 of the drive assembly 60. In aspects of the disclosure, the distal portion of the core member 70 is secured to the working end 60 of the drive assembly 60 by welding. Alternately, other techniques can be used to secure the working end 60 of the drive assembly 52 to the flexible beam 74 such as interlocking structure, e.g., dovetail connectors. In aspects of the disclosure, the core member 70 can be formed of stainless steel, e.g., stainless steel 301, although it is envisioned that other metals can be used to form the core member 70. It is also envisioned that the core member 70 can be formed from stacked sheets of metal.

The outer laminates 72 of the drive beam assembly 62 are secured to the side walls 76 of the core member 70. In aspects of the disclosure, the outer laminates 72 are formed of a flexible material that has a lower coefficient of friction than the core member 70. In some aspects of the disclosure, the outer laminates 72 are formed from polytetrafluoroethylene (PTFE) although the use of other materials to form the outer laminates 72 is also envisioned such as nylons and polypropylene. It is envisioned that the material selected to form the outer laminates reduces the coefficient of friction between the drive beam assembly 62 and the metal components of the tool assembly 16 to between about 0.05 and 0.2.

In aspects of the disclosure, the outer laminates 72 are coupled together by a top wall 82 to form a U-shaped laminate assembly 83 that defines a cavity 84 with the outer laminates 72. The cavity 84 is dimensioned to receive the core member 70. The U-shaped laminate assembly 83 defines an opening 86 (FIG. 4 ) that is positioned opposite to the top wall 82 that allows passage of the laminate assembly 83 about the core member 70 such that the outer laminates 72 are positioned along the side walls 76 of the core member 70.

In aspects of the disclosure, the bottom wall 80 of the core member 70 defines notches 88 and one of the outer laminates 72 includes fingers 90 that extend across the opening 86 (FIG. 5 ) of the laminate assembly 83. The fingers 90 are positioned to be received within the notches 88 of the core member 70. When the U-shaped laminate assembly 83 is slid onto the core member 70 in the direction indicated by arrows “A” in FIGS. 4 and 7 , the fingers 90 engage one of the side walls 76 of the core member 70 to deform the outer laminate 72 supporting the fingers 90 outwardly in the direction of arrow “B”. When the fingers 90 are moved into alignment with the notches 88 in the core member 70, the outer laminate 72 supporting the fingers 90 snaps inwardly in the direction indicated by arrow “C” in FIG. 8 to position the fingers 90 within the notches 88 and secure the U-shaped laminate assembly 83 about the core member 70.

FIG. 10 illustrates the tool assembly 16 articulated ninety-degrees with the drive assembly 52 in a partially advanced or clamping position to move the tool assembly 16 to the clamped position. For a detailed description of the interaction between the drive assembly 52 and the tool assembly 16, see the '534 Patent. In this position, the drive beam assembly 62 is bent ninety-degrees at a position adjacent the pivot member 26.

FIG. 11 illustrates the drive assembly 52 advanced to fire or actuate the tool assembly 16. When the drive assembly 52 is advanced to fire the stapling device 10 with the tool assembly in an articulated position, the drive beam assembly 62 is advanced along a ninety-degree bend in the direction of arrows “D” to advance the working end 60 of the drive assembly 52 through the tool assembly 16. Advancement of the working end 60 through the tool assembly 16 advances an actuation sled through the tool assembly 16 to eject staples from the staple cartridge 44 and cut tissue clamped between the anvil assembly 32 and the cartridge assembly 34. By providing outer laminates 72 on each side 76 of the core member 70, the frictional forces on the drive assembly 52 are substantially reduced to lower the forces required to fire the stapling device 10 (FIG. 1 ).

FIGS. 12-14 illustrate an alternative version of the drive assembly 52 of the stapling device 10 shown generally as drive assembly 152. The drive assembly 152 includes a working end 160 and a flexible drive beam assembly 162. The working end 160 of the drive assembly 152 is identical to the working end 60 (FIG. 4 ) of the drive assembly 52 and will not be described in further detail herein. The flexible drive beam assembly 162 includes a core member 170 and outer laminates 172. The core member 170 defines elongated openings 174 that extend between side walls 176 of the core member 170 through the core member 170. Each of the outer laminates 172 defines elongated openings 178 that are aligned with the elongated openings 174 in the core member 170 and extend through the outer laminate 172. Each of the elongated openings 178 is bounded by an inwardly projecting rib 180 that is received within a respective one of the openings 174 in the core member 170 to secure the outer laminates 172 to the side walls 176 of the core member 170. In aspects of the disclosure, the ribs 180 of the outer laminates 172 can be secured together such as by ultrasonic welding to secure the outer laminates 172 to the opposite sides 176 of the core member 170.

The core member 170 and the outer laminates 172 in this version of the drive assembly and versions of the drive assembly described below are formed of the materials identified above regarding core member 70 and outer laminates 72 and will not be described in further detail herein.

FIGS. 15-18 illustrate an alternative version of the drive assembly 52 (FIG. 4 ) of the stapling device 10 shown generally as drive assembly 252. The drive assembly 252 includes a working end 260 and a flexible drive beam assembly 262. The working end 260 of the drive assembly 252 is identical to the working end 60 (FIG. 4 ) of the drive assembly 52 and will not be described in further detail herein. The flexible drive beam assembly 262 includes a core member 270 and outer laminates 272 that are coupled together by top and bottom walls 282 to form a rectangular laminate assembly 283 that defines a cavity 286. The cavity 286 is dimensioned to slidably receive the core member 270. In aspects of the disclosure, top and bottom walls 278 and 280 of the core member 270 include protrusions 288 that include a proximally facing ramped surface and a distal stop surface that is perpendicular to a longitudinal axis of the core member 270. The rectangular laminate assembly 283 includes a distal portion having cutouts 290 in top and bottom walls 282 a and 282 b of the laminate assembly 283. When the core member 270 is received within the cavity 286 and the laminate assembly 283 is slid in the direction of arrows “E” in FIG. 16 , the protrusions 288 are received in the cutouts 290 to secure the laminate assembly 283 to about the core member 270.

In aspects of the disclosure, the distal portion of the laminate assembly 283 includes slots 292 (FIG. 15 ) that provide flexibility to the distal portion of the laminate assembly 283 to allow the top and bottom walls 282 of the laminate assembly 283 to flex outwardly in the direction of arrows “F” in FIG. 17 to allow the protrusions 288 on the core member 270 to pass into the cutouts 290 in the laminate assembly 283. Once the protrusions 288 pass into the cutouts 290, the distal portion of the laminate assembly 283 returns to its unbiased position to secure the laminate assembly 283 to the core member 270.

FIGS. 19 and 20 illustrate an alternative version of the drive assembly 252 (FIG. 15 ) of the stapling device 10 shown generally as drive assembly 352. The drive assembly 352 is substantially similar to the drive assembly 252 except that the cutouts 390 in the rectangular laminate assembly 383 are formed on a distal extension 372 a of the outer laminates 372 rather than on the top and bottom walls of the laminate assembly, and the protrusions 388 are formed on the vertical strut 368 of the working end 360 of the drive assembly 352 rather than on top and bottom walls of the core member. When the laminate assembly 383 is slid onto the core member 370 in the direction of arrows “G” in FIG. 20 , the protrusions 388 on the vertical strut 368 of the working end 360 of the drive assembly 352 are received within the cutouts 390 formed in the distal extensions of the outer laminates 372 in the same manner protrusions 288 (FIG. 18 ) are received in the cutouts 290, to secure the laminate assembly 383 to the core member 370.

FIG. 21 illustrates another alternative version of the drive assembly 52 of the stapling device 10 shown generally as drive assembly 452. The drive assembly 452 includes a working end 460 and a flexible drive beam assembly 462. The working end 460 of the drive assembly 452 is identical to the working end 60 (FIG. 4 ) of the drive assembly 52 and will not be described in further detail herein. The flexible drive beam assembly 462 includes a core member 470 and outer laminates 472 that are coupled together by top and bottom walls 482 to form a rectangular laminate assembly 483 that defines a cavity 486. The cavity 486 receives the core member 470. In aspects of the disclosure, the core member 470 and the outer laminates 472 define openings 492 that receive pins or dowels 494 to secure core member 470 to the outer laminates 472 within the cavity 486.

FIGS. 22-24 illustrate another alternative version of the drive assembly 52 of the stapling device 10 shown generally as drive assembly 552. The drive assembly 552 includes a working end 560 and a flexible drive beam assembly 562. The working end 560 of the drive assembly 552 is identical to the working end 60 (FIG. 4 ) of the drive assembly 52 and will not be described in further detail herein. The flexible drive beam assembly 562 includes a core member 570 and outer laminates 572. In aspects of the disclosure, each of the outer laminates 572 defines a stepped opening 574 and includes an inwardly extending protrusion 594 with an enlarged head 596. The core member 570 defines elongated slots 598 that are aligned with the protrusions 594. The protrusions 594 are positioned through the elongated slots 598 in the core member 570 and pressed into the stepped openings 574 of the other outer laminate 572 to secure the outer laminates 572 to each other and to the core member 570. By providing elongated slots 598 in the core member 570, the outer laminates 572 can slide in unison in relation to the core member 570. It is envisioned that each of the outer laminates 572 may include one protrusion 594 and define one opening 574, or one of the outer laminates 572 can define two openings 574 and the other of the outer laminates 572 can include two protrusions 594.

FIGS. 25 and 26 illustrate other alternative versions of the drive assembly 52 of the stapling device 10 shown generally as drive assemblies 652 and 752. In the drive assembly 652, the outer laminates 672 and the core member 670 of the drive beam assembly 662 define openings 674 and 676, respectively, that are aligned with each other. The openings 674 and 676 receive a grommet 678 (FIG. 25 ) that secures the outer laminates 672 to the core member 670. In this aspect of the disclosure, the grommet 678 includes outer ends 680 that diverge and engage angled surfaces 682 of the outer laminates 672 that define a portion of the openings 674 to tightly secure the outer laminates 672 to the core member 670.

The drive assembly 752 (FIG. 26 ) is substantially the same as the drive assembly 652 (FIG. 25 ) except that the outer laminates 772 are secured to each other and to the core member 770 using a tubular rivet 778. In this aspect of the disclosure, the openings 774 in the outer laminates 772 are stepped and receive head portions 780 of the rivet 778 to secure the outer laminates 772 to each other and to the core member 770.

Persons skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. It is envisioned that the elements and features illustrated or described in connection with one exemplary embodiment may be combined with the elements and features of another without departing from the scope of the disclosure. As well, one skilled in the art will appreciate further features and advantages of the disclosure based on the above-described embodiments. Accordingly, the disclosure is not to be limited by what has been particularly shown and described, except as indicated by the appended claims. 

What is claimed is:
 1. A drive assembly comprising: a working end having an I-beam configuration including a first beam, a second beam, and a vertical strut interconnecting the first beam to the second beam; and a drive beam assembly including a core member and outer laminates, the core member including a flexible beam having planar side walls, a top wall, and a bottom wall, the flexible beam having a distal portion secured to the working end, the outer laminates supported along the planar side walls of the flexible beam such that longitudinal movement of the core member causes longitudinal movement of the outer laminates and the working end, wherein the core member is formed from a metal and the outer laminates are formed from a material having a lower coefficient of friction than the core member.
 2. The drive assembly of claim 1, wherein the outer laminates are formed from polytetrafluoroethylene.
 3. The drive assembly of claim 2, wherein the core member is formed from stainless steel.
 4. The drive assembly of claim 1, wherein the outer laminates are coupled together by a top wall to form a U-shaped laminate assembly that defines a cavity and an opening opposite the top wall, the cavity receiving the core member through the opening.
 5. The drive assembly of claim 4, wherein the bottom wall of the core member defines notches and one of the outer laminates includes fingers that are aligned with the notches and extend into the opening, the fingers received within the notches in snap-fit fashion when the U-shaped laminate assembly is positioned on the core member to secure the U-shaped laminate assembly on the core member.
 6. The drive assembly of claim 1, wherein the core member defines openings, and each of the outer laminates defines openings that are aligned with the openings in the core member, the openings in the outer laminates being bounded by inwardly projecting ribs that are received within the openings in the core member, the inwardly extending ribs on the outer laminates being secured together within the openings of the core member to secure the outer laminates to opposite sides of the core member.
 7. The drive assembly of claim 1, wherein the outer laminates are coupled together with top and bottom walls to form a rectangular laminate assembly, the rectangular laminate assembly defining a cavity that receives the core member.
 8. The drive assembly of claim 7, wherein each of the top and bottom walls of the core member includes a protrusion and each of the top and bottom walls of the rectangular laminate assembly defines a cutout that receives one of the protrusions to secure the rectangular laminate assembly on the core member.
 9. The drive assembly of claim 7, wherein each of the outer laminates includes a distal extension that defines a cutout, and the working end of the drive assembly includes protrusions, the protrusions received within the cutouts to secure the rectangular laminate assembly to the core member.
 10. The drive assembly of claim 7, wherein the outer laminates and the core member define openings and the rectangular laminate assembly is secured to the core member with fasteners selected from the group consisting of pins, dowels, rivets, and grommets, the fasteners extending through the openings.
 11. The drive assembly of claim 1, wherein each of the outer laminates defines an opening and includes a protrusion, and the core member includes elongate slots that receive the protrusions of the outer laminates, the protrusion of each of the outer laminates received within the opening of the other of the outer laminates to secure the outer laminates to each other and to the core member, the elongate slots in the core member facilitating relative movement between the outer laminates and the core member.
 12. A stapling device comprising: an adapter assembly defining a longitudinal axis and having a proximal portion and a distal portion; a tool assembly supported on the distal portion of the adapter assembly by a pivot member that defines a pivot axis that is transverse to the longitudinal axis such that the tool assembly can articulate between a non-articulated position and articulated positions about the pivot axis, the tool assembly including an anvil assembly and a cartridge assembly that are movable in relation to each other between open and clamped positions; and a drive assembly movable in relation to the tool assembly between retracted and advanced positions to actuate the tool assembly, the drive assembly including: a working end having an I-beam configuration including a first beam, a second beam, and a vertical strut interconnecting the first beam to the second beam; and a drive beam assembly including a core member and outer laminates, the core member including a flexible beam having planar side walls, a top wall, and a bottom wall, the flexible beam having a distal portion secured to the working end, the outer laminates supported along the planar side walls of the flexible beam such that longitudinal movement of the core member causes corresponding longitudinal movement of the outer laminates and the working end, wherein the core member is formed from a metal and the outer laminates are formed from a material having a lower coefficient of friction than the core member.
 13. The stapling device of claim 12, wherein the outer laminates are formed from polytetrafluoroethylene.
 14. The stapling device of claim 13, wherein the core member is formed from stainless steel.
 15. The stapling device of claim 12, wherein the outer laminates are coupled together by a top wall to form a U-shaped laminate assembly that defines a cavity and an opening opposite the top wall, the cavity receiving the core member through the opening.
 16. The stapling device of claim 15, wherein the bottom wall of the core member defines notches and one of the outer laminates includes fingers that are aligned with the notches and extend into the opening, the fingers received within the notches in snap-fit fashion when the U-shaped laminate assembly is positioned on the core member to secure the U-shaped laminate assembly on the core member.
 17. The stapling device of claim 12, wherein the core member defines openings, and each of the outer laminates defines openings that are aligned with the openings in the core member, the openings in the outer laminates being bounded by inwardly projecting ribs that are received within the openings in the core member, the inwardly extending ribs on the outer laminates being secured together within the openings of the core member to secure the outer laminates to opposite sides of the core member.
 18. The stapling device of claim 12, wherein the outer laminates are coupled together with top and bottom walls to form a rectangular laminate assembly, the rectangular laminate assembly defining a cavity that receives the core member.
 19. The stapling device of claim 18, wherein each of the top and bottom walls of the core member includes a protrusion and each of the top and bottom walls of the rectangular laminate assembly defines a cutout that receives one of the protrusions to secure the rectangular laminate assembly on the core member.
 20. The stapling device of claim 18, wherein each of the outer laminates includes a distal extension that defines a cutout, and the working end of the drive assembly includes protrusions, the protrusions received within the cutouts to secure the rectangular laminate assembly to the core member. 